In this paper, a network-based monitoring unit for condition monitoring and fault diagnosis of rotating machinery is designed and implemented. With the technology of DSP( Digital signal processing), TCP/IP, and simultaneous acquisition, a mechanism of multi-process and inter-process communication, the integrating problem of signal acquisition, the data dynamic management and network-based configuration in the embedded condition monitoring system is solved. It offers the input function of monitoring information for network-based condition monitoring and a fault diagnosis system.